1. Field of the Invention
The present invention relates generally to the field of disk drives and more particularly to suspensions for heads thereof.
2. Description of the Prior Art
Magnetic, optical, and magneto-optical disk drives store and retrieve data for digital electronic apparatuses such as computers and entertainment devices. FIG. 1 shows that the typical disk drive comprises a head 100 in very close proximity to a surface of a rotatable disk 110. FIG. 2 show a side view of the head 100 over the disk 110. As shown in FIG. 2, the head 100 includes a slider 200 and a transducer 210. The transducer 210, in turn, includes a read element and optionally a write element. As the disk 110 rotates beneath the head 100, a very thin air bearing is formed between the surface of the disk 110 and an air bearing surface (ABS) of the slider 200. The air bearing causes the head 100 to “fly” above the surface of the disk 110. As the head 100 flies over the disk 110, the write element and the read element can be alternately employed to write and read data bits along data tracks on the disk 110.
In order to keep the head 100 properly oriented and at the correct height above the disk 110 while in flight, disk drives employ a head gimbal assembly (HGA) that comprises the head 100 and a suspension that further includes a load beam 220 and a flexure 230 that attaches the head 100 to the load beam 220.
In some disk drives, when not in operation, the head 100 comes to rest on the surface of the disk 110 in a designated area known as a parking zone. In these disk drives the parking zone cannot be used for data storage. For this and other reasons, in some disk drives the head 100 is instead parked on a load/unload ramp disposed proximate to the outer diameter of the disk 110. FIG. 3 illustrates two HGAs 300, 310, in up and down configurations, respectively, for accessing opposite sides of the disk 110 (not shown in FIG. 3). In FIG. 3 the HGAs 300, 310 are engaged with a load/unload ramp 320. More specifically, a lifter tab 240 (see FIG. 2) that extends from the load beam 220 engages the load/unload ramp 320.
Because of the close proximity of the HGAs 300, 310 when parked on the load/unload ramp 320, and because of the flexibility of the flexures 230, the heads 100 of the respective HGAs 300, 310 can collide with each other if the disk drive experiences a mechanical shock, such as when dropped. To prevent such collisions, and/or to prevent excessive deflection of the flexures 230 that might lead to yielding and plastic deformation, some load/unload ramps 320 include a gimbal-limiting surface 330 for each HGA 300, 310, and each flexure 230 includes a limiter tab 250 (see FIG. 2), also known as a 3rd limiter. As shown in FIG. 3, the limiter tabs 250 do not typically touch the gimbal-limiting surfaces 330 except as necessary to prevent the heads 100 from exceeding an acceptable range of motion.
As requirements for the shock performance have increased, limiter tabs have been made more stiff by making the limiter tabs wider. FIG. 4 illustrates a bottom view of one such design. In FIG. 4, a head 400 is attached to a suspension 410 that comprises a flexure 420 having a limiter tab 430 extending from a trailing edge thereof. Unfortunately, widening the limiter tab 430 for increased stiffness also undesirably increases the total mass and inertia of the HGA. Also, widening the limiter tab 430 may begin to interfere with design options for tabs 440, used to hold the suspension 410 to a carrier strip (not shown) prior to separation from the carrier strip (a.k.a. “de-tabbing”).
Accordingly, there is a need in the art for a stiffer limiter tab that adds less mass and inertia to the HGA.